PURPOSE: In this study, we investigated the potential of injectable hydrogel scaffolds for the regeneration of nucleus pulposus. MATERIALS AND METHODS: We prepared injectable hydrogels [Chitosan-Pluronic (CP), CP/Osteogenic Protein-1 (CP/OP-1), CP/Gly-Arg-Gly-Asp-Ser (CP/GRGDS), CP/GRGDS/OP-1] for this study. One of the four potential materials was selected through the cell viability tests. For each material, primary cultured nucleus pulposus (NP) cells from New Zealand rabbits were seeded onto each material. For the investigation of the effects of mechanical stimulation, the commercially available bioreactor was used. 0.2 MPa of intermittent hydrostatic pressure was imposed for 3 days after 7th day of seeding with the pattern of 2 min and 15 min for stimulating and resting, respectively. The specimens were harvested at 1, 10, 14 day after seeding for analyses. RESULTS: The MTT assay for 5 days revealed that CP/OP-1 group showed significant increase. The other two groups (CP/GRGDS and CP/GRGDS/OP-1) showed that the proliferation rate increased until 3 days after culture, while it decreased on day 5. The mechanical stimuli induced higher amounts of DNA measured in CP/OP- 1 on day 5 after culture. However, no significant difference was observed between two groups. CONCLUSION: We came to the conclusions that the biochemical environment as well as mechanical stimulation may play an important role in regenerating nucleus pulposus matrix, especially in CP/OP-1 in this study. However, further study are recommended in relation to mechanical effects as well as biochemical conditions.
Bioreactors ; Cell Survival ; DNA ; Hydrogel ; Hydrogels ; Hydrostatic Pressure ; Intervertebral Disc ; Porphyrins ; Rabbits ; Regeneration ; Seeds

OBJECTIVE: In order to facilitate total removal with preservation of the facial nerve, the authors applied presigmoid(PS) approach in some patients with recurrent acoustic neurinoma(AN) patients who had undergone previous retrosigmoid(RS) approaches. The surgical outcomes of PS approach were retrospectively analyzed and compared to those of RS approaches and we suggest the indication of PS approach for recurrent AN. METHODS: From 1989 to 1999, twenty-one of 183 operated AN patients underwent re-operation due to regrowth of the residual tumors. Nine of the 21 recurrent tumors were removed by PS approach and 12 cases underwent RS approach. The surgical extent of removal and the facial nerve preservation rate were compared between the two different approaches. RESULTS: In PS approaches, the total removal was achieved in four patients(44%) and the facial nerve could be identified and preserved anatomically in all patients. Among 12 cases who underwent RS approaches, the rate of total removal was 44% and the facial nerve identified and preserved in only 5 cases (42%). The rate of facial nerve preservation was significantly different between two modes of approaches (p=0.0007). CONCLUSION: PS transpetrosal approach is recommended in recurrent AN patients who had underwent RS approach previously and already lost the hearing. Early identification of the facial nerve and easy removal of the tumors can be achieved using the PS approach.
Acoustics* ; Facial Nerve ; Hearing ; Humans ; Neoplasm, Residual ; Neuroma, Acoustic* ; Recurrence ; Retrospective Studies

Cardiac papillary fibroelastomas are associated with a high risk of systemic embolization in spite of benign nature. We report a case of 85-year-old patient with left supraclinoid internal carotid artery occlusion who treated with aspiration thrombectomy. Despite of the absence of residual mass on echocardiography, we could analyze pathologic specimens using retrieved embolus and confirmed cardiac papillary fibroelastoma as a rare cause of stroke.

PURPOSE: For the research of Boron Neutron Capture Therapy (BNCT), fast neutrons generated from the MC-50 cyclotron with maximum energy of 34.4 MeV in Korea Cancer Center Hospital were moderated by 70 cm paraffin and then the dose characteristics were investigated. Using these results, we hope to establish the protocol about dose measurement of epi-thermal neutron, to make a basis of dose characteristic of epi-thermal neutron emitted from nuclear reactor, and to find feasibility about accelerator-based BNCT. METHOD AND MATERIALS: For measuring the absorbed dose and dose distribution of fast neutron beams, we used Unidos 10005 (PTW, Germany) electrometer and IC-17 (Far West, USA), IC-18, EIC-1 ion chambers manufactured by A-150 plastic and used IC-17M ion chamber manufactured by magnesium for gamma dose. There chambers were flushed with tissue equivalent gas and argon gas and then the flow rate was 5 cc per minute. Using Monte Carlo N-Particle (MCNP) code, transport program in mixed field with neutron, photon, electron, two dimensional dose and energy fluence distribution was calculated and there results were compared with measured results. RESULTS: The absorbed dose of fast neutron beams was 6.47x10-3 cGy per 1 MU at the 4 cm depth of the water phantom, which is assumed to be effective depth for BNCT. The magnitude of gamma contamination intermingled with fast neutron beams was 65.2+/-0.9% at the same depth. In the dose distribution according to the depth of water, the neutron dose decreased linearly and the gamma dose decreased exponentially as the depth was deepened. The factor expressed energy level, D20/D10, of the total dose was 0.718. CONCLUSION: Through the direct measurement using the two ion chambers, which is made different wall materials, and computer calculation of isodose distribution using MCNP simulation method, we have found the dose characteristics of low fluence fast neutron beams. If the power supply and the target material, which generate high voltage and current, will be developed and gamma contamination was reduced by lead or bismuth, we think, it may be possible to accelerator-based BNCT.
Argon ; Bismuth ; Boron Neutron Capture Therapy* ; Boron* ; Cyclotrons ; Electric Power Supplies ; Fast Neutrons* ; Hope ; Korea ; Magnesium ; Neutrons ; Nuclear Reactors ; Paraffin ; Plastics ; Water

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) can develop in chronic hepatitis B (CHB) patients with normal alanine aminotransferase (ALT) levels. Therefore, methods that can stratify an individual's HCC risk are needed. METHODS: A simple HCC risk score was developed from 971 patients with CHB who had elevated hepatitis B virus DNA levels (>2,000 IU/mL) with normal or mildly elevated ALT levels (<80 U/L). The score was validated from an independent cohort of 507 patients. RESULTS: A 4-point risk scale was developed, with HCC risk ranging from 0% to 17.8% at 5 years for the lowest and highest risk scores. The D2AS score had high area under the receiver operating curves (AUROCs) for predicting development of HCC at 3/5 years (0.895/0.884). The calculated AUROCs to predict the development of HCC at 3/5 years were 0.889/0.876 in the validation cohort, with 5-year HCC incidence rates ranging from 0% to 13.8% at 5 years for the lowest and highest risk scores. CONCLUSIONS: The D2AS risk score can play a valuable role in risk stratification and may be useful for guiding clinical decisions for enhanced surveillance or treatment to reduce the HCC risk in CHB patients with normal or mildly elevated ALT levels.
Alanine Transaminase* ; Alanine* ; Carcinoma, Hepatocellular* ; Cohort Studies ; DNA ; Hepatitis B ; Hepatitis B virus ; Hepatitis B, Chronic* ; Hepatitis, Chronic* ; Humans ; Incidence ; Liver Function Tests

BACKGROUND: It has been well recognized that exercise tolerance and angina threshold in patients with coronary artery disease (CAD) are reduced after a meal. But precise mechanism leading to the postprandial worsening of angina has yet to be adequately defined. This study was undertaken to determine the effect of a mixed meal on cardiac performance and heart rate variability (HRV) in patients with CAD. METHODS: 24 patients with angina or myocardial infarction were studied. Echocardiographic examination and heart rate variability test were performed in the fasting state and the other 40-60 minutes after a 600-800 kcal mixed meal. RESULTS: In the postprandial state, resting heart rate was significantly increased by 5.2% from 64.8+/-10.69 beats/min to 68.2+/-10.2 beats/min (p<0.01), stroke volume by 8.1% from 59.6+/-17.3 ml to 64.4+/-18.1 ml (p<0.01), cardiac output by 14.2% from 3.8+/-1.06 to 4.3+/-1.21 (p<0.01). E wave and A wave of mitral filling flow and E/A ratio were not significantly different in the fasting and postprandial tests. But DT and IVRT were significantly increased in the postprandial state (p<0.05, p<0.01 respectively). HRV was not different in the fasting and postprandial state. CONCLUSIONS: In patients with CAD, a 600-800 kcal mixed meal significantly increased resting heart rate, stroke volume, cardiac output, DT and IVRT.
Cardiac Output ; Coronary Artery Disease ; Echocardiography ; Exercise Tolerance ; Fasting ; Heart Rate ; Humans ; Meals* ; Myocardial Infarction ; Stroke Volume

PURPOSE: This study aimed to evaluate the initial outcomes of proton beam therapy (PBT) for hepatocellular carcinoma (HCC) in terms of tumor response and safety. MATERIALS AND METHODS: HCC patients who were not indicated for standard curative local modalities and who were treated with PBT at Samsung Medical Center from January 2016 to February 2017 were enrolled. Toxicity was scored using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Tumor response was evaluated using modified Response Evaluation Criteria in Solid Tumors (mRECIST). RESULTS: A total of 101 HCC patients treated with PBT were included. Patients were treated with an equivalent dose of 62–92 GyE10. Liver function status was not significantly affected after PBT. Greater than 80% of patients had Child-Pugh class A and albumin-bilirubin (ALBI) grade 1 up to 3-months after PBT. Of 78 patients followed for three months after PBT, infield complete and partial responses were achieved in 54 (69.2%) and 14 (17.9%) patients, respectively. CONCLUSION: PBT treatment of HCC patients showed a favorable infield complete response rate of 69.2% with acceptable acute toxicity. An additional follow-up study of these patients will be conducted.
Carcinoma, Hepatocellular ; Follow-Up Studies ; Humans ; Liver ; Proton Therapy ; Protons ; Radiotherapy ; Response Evaluation Criteria in Solid Tumors

PURPOSE: The purpose of this study was to investigate the feasibility and survival benefits of combined treatment with radiotherapy and adjuvant temozolomide (TMZ) in a Korean sample. MATERIALS AND METHODS: A total of 750 Korean patients with histologically confirmed glioblastoma multiforme, who received concurrent chemoradiotherapy with TMZ (CCRT) and adjuvant TMZ from January 2006 until June 2011, were analyzed retrospectively. RESULTS: After the first operation, a gross total resection (GTR), subtotal resection (STR), partial resection (PR), biopsy alone were achieved in 388 (51.7%), 159 (21.2%), 96 (12.8%), and 107 (14.3%) patients, respectively. The methylation status of O6-methylguanine-DNA methyltransferase (MGMT) was reviewed retrospectively in 217 patients. The median follow-up period was 16.3 months and the median overall survival (OS) was 17.5 months. The actuarial survival rates at the 1-, 3-, and 5-year OS were 72.1%, 21.0%, and 9.0%, respectively. The median progression-free survival (PFS) was 10.1 months, and the actuarial PFS at 1-, 3-, and 5-year PFS were 42.2%, 13.0%, and 7.8%, respectively. The patients who received GTR showed a significantly longer OS and PFS than those who received STR, PR, or biopsy alone, regardless of the methylation status of the MGMT promoter. Patients with a methylated MGMT promoter also showed a significantly longer OS and PFS than those with an unmethylated MGMT promoter. Patients who received more than six cycles of adjuvant TMZ had a longer OS and PFS than those who received six or fewer cycles. Hematologic toxicity of grade 3 or 4 was observed in 8.4% of patients during the CCRT period and in 10.2% during the adjuvant TMZ period. CONCLUSION: Patients treated with CCRT followed by adjuvant TMZ had more favorable survival rates and tolerable toxicity than those who did not undergo this treatment.
Biopsy ; Chemoradiotherapy* ; Disease-Free Survival ; Follow-Up Studies ; Glioblastoma* ; Humans ; Korea* ; Methylation ; Radiotherapy ; Retrospective Studies* ; Survival Rate

Purpose: Alpha-fetoprotein (AFP) is a prognostic marker for hepatocellular carcinoma (HCC). We investigated the prognostic value of AFP levels in patients who achieved complete response (CR) to transarterial chemoembolization (TACE) for HCC. Materials and Methods: Between 2005 and 2018, 890 patients with HCC who achieved a CR to TACE were recruited. An AFP responder was defined as a patient who showed elevated levels of AFP (>10 ng/mL) during TACE, but showed normalization or a >50% reduction in AFP levels after achieving a CR. Results: Among the recruited patients, 569 (63.9%) with naïve HCC and 321 (36.1%) with recurrent HCC after complete resection were treated. Before TACE, 305 (34.3%) patients had multiple tumors, 219 (24.6%) had a maximal tumor size >3 cm, and 22 (2.5%) had portal vein tumor thrombosis. The median AFP level after achieving a CR was 6.36 ng/mL. After a CR, 473 (53.1%) patients experienced recurrence, and 417 (46.9%) died [median progression-free survival (PFS) and overall survival (OS) of 16.3 and 62.8 months, respectively]. High AFP levels at CR (>20 ng/mL) were independently associated with a shorter PFS [hazard ratio (HR)=1.403] and OS (HR=1.284), together with tumor multiplicity at TACE (HR=1.518 and 1.666, respectively). AFP non-responders at CR (76.2%, n=359 of 471) showed a shorter PFS (median 10.5 months vs. 15.5 months, HR=1.375) and OS (median 41.4 months vs. 61.8 months, HR=1.424) than AFP responders (all p=0.001). Conclusion High AFP levels and AFP non-responders were independently associated with poor outcomes after TACE. AFP holds clinical implications for detailed risk stratification upon achieving a CR after TACE.